Electric connecter



Nov. 1, 193s.

A. A. BOON ET AL ELECTRIC CONNECTER Filed May 11, 1937 .6 a y W M M w ATTORNEYj ."*e* 93s l d-35.163

. Anthonie Adrianus Boonfand Hans Barknowitz, Amsterdam, and Gerard -Martin Uitermark, Haarlem, Netherlands. asslgnors to Louis De Jong, ,Netherlands A Application may 113937, Serial No. 141,886 g In the Netherlands December 7,1936

sclaims. (cilia- 35s) 1 This invention relates toelectric connecters adapted to receive and hold electric lamp bulbs h or electric plugs, wherein means are provided for preventing the unauthorized insertion or removal 5 of lamp bulbs or plugs, or the unauthorized use of the sockets as sources of electric energy. This invention is particularly directed to' the provision of a socket of this type which is simple in construction; and simple and reliable in .opera Qne feature of lamp socketsin common use at the present time is. the facility with which lamps may be inserted and withdrawn, andreplaced by plugs, for various electrical appliances.

while this is often a great advantage, in someinstances it .is a decided disadvantage. For ,ex-' ample, lamps placed in public conveyances,-public rooms and other exposed places are often removed and carried away by thieves. The preven-.

tion of such thefts, or the apprehension of. the

thieves, is oftenan' impossible task. Also, particularly in hotels and boarding houses, electric lamps are often removed from their sockets and replaced by plugs for various appliances such as flatirons, electric stoves, grills, etc., despite express agreement not to do so, thereby using the house current without compensation therefor. Furthermore, in many places, such as warehouses, storerooms, etc., more electric sockets may be provided than is oi'dinarilynecessary for the adequate illumination of the area,'so that the management removes bulbs from some sockets or turns thosesockets oil. In such cases .it may happen that an irresponsible employee will turn on the lights again, or will replace bulbs in the empty sockets, as the case may be. In

either event a needless waste of electric current ensues. a

. The present invention is directed especially 40 to the provision-of alamp socket which is adapted to prevent the unauthorized insertion of a lamp in the socket, the unauthorized removal of a lamp from-the socket, and the unauthorized use of a lamp which it is'de'sired to leav'e in-the socket in'readiness for. future use. In its preferred form, the actof locking the lamp in the socket establishesan electric circuit thereto, and

the'act of unlocking the lamp breaks the circuit. In some cases sockets are wired together .ingroups and controlleg'l.- from a single master 4 switch, without the provision of an individual switch foreach socket. In such a case the con tacts a socket are always alive when the V master-switch is closed, and when a bulb is rep moved from a socket -the exposed-live contacts .tively, of one of the locking plungers; A

pressed locking plungers in place;-and

constitute a source of danger. In accordance with the present invention a socket may be constructed in-which the removalof the bulb necessarily breaks the circuit to theiinner contacts of the socket. Furthermore, if there are no individual switches for,the sockets, the invention provides means for insuring that the lamps are kept in .the'circuit without danger of the lamps being turned off without authority, yetpermits the individual turning of! of the lamps, when dem sired, by the use of a special key.

Heretofore a number of deviceshavebeen proposed to perform one or more of the above func- 1 Hubs, particularly that of; preventing theunauthorized removal of the bulb.' In some-of these 1 proposals special elements must be attached to the lamp bases ;'.in some, special attachments for ordinary sockets are provided; and in some, the

mechani'sm for accomplishing the desired results f isinefiective, unreliable or too complicated. The

connecter of the present invention is designed to function in a simple, direct and positive manner, andto be easily and economically manufactured.

' For an understanding of the invention reference is had to the drawin which illustrates a 25 specific embodimentofthe lnventionyand. t e

following description thereof. v

- In the'drawlng: f

Fig. 1 is a longitudinal section of a connecter madein accordance with-the invention, with a 30 conventional lamp inserted; Fig. 2 is 'a' longitudinal section of the casing alone;

Fig. 3 is alongitudinal section of the screwlt l5 on-the line 3-4 of Fig. 31:; Fig, 3a a 35.

view thereof. at right angles to the slot; V

Fig. 4 is aside view of a key adaptedt'o un-' lock the screw-bolt l5; Fig. 4a is an edge view thereof;

Fig. 6=is a detail view -of"'one .of. the springs. forthe locking plungers; and

Figs. Wand 7a are side and end vlews,.respectively, of one 'of the screws which hold the spring- Fig. 8 is'a detail showing the. lungers 2| mounted to lock the screw-bolt in-open, as well as closed; position.

Referring to the drawing, a casing, preferto i -ably of non-conducting material such as a phenolic condensation product known by the tradename Bakelite; is provided with a lamp socket ll adapted to receive a vconventional electric lamp [2 having a screw-base ll. Lamp socket. II M Figs. 5 and 5a are end and side views, respec- .casing ll of the connecter may have the usual threaded brass insert, if desired. Casing I0 is also provided with a screw socket ll into which screw-bolt I! (Fig. 3) is screwed. A brass ring it is mounted at the inner end of the screw-socket and connected with conductor H which extends to the outside of the connecter to permit ready wiring into a circuit. Conductor l'l may be secured to the casing ID of the connecter inany convenient manner, such as shown. The inner end of the screw-socket and the brass ring l6 are preferably beveled so as to make good electrical contact with the screwbolt when the latter is advanced.

The leading end of screw-bolt I5 is shaped to fit the inner end of the screw-socket H, and provided with a brass ring l8 so as to make a good electrical contact with ring IS in the screwsocket. The front end IQ of the screw-bolt is sharpened, and is preferably of a relatively hard the screw-bolt to the lamp. To diminish resistance, and to insure making a good electrical contact between conductor l1 and lamp base IS, the brass shell It may be extended nearly to the point IQ of the screw-bolt. With proper-construction, electric current may flow to the lampbase not only through the point l9, but also, if socket II is provided with the usual brass insert, from screw-bolt to the brass insert and then to the lamp base. The usual spring contact is provided to make contact with the central terminal of the lamp base and may be fastened to the in any convenient manner, such as shown.

The screw-bolt I I is locked in position by spring-pressed plungers 2| which project into the slot 22 (Fig. 3a) in the shank of the screw-bolt on opposite sides thereof. The parts of the plunger mechanism are .shown in Figs. 5 to 7a. Spring 23 fits around the shank 24 of the plunger and both spring and plunger are retained in the casing H of theconnecter by the short screw 25.

The inner end 28 of the slot in the screw-bolt (Fig. 3) has an irregular profile to receive key 2'| for unlocking the screw-bolt. When the key is inserted it forces the plungers 2| out of the slot, thus releasing the screw-bolt and allowing it't'o turn. Plungers 2| are staggered with respect to each other to make it difficult to unlock the screw-bolt without the proper key. In Fig. 1 the plungers are so positioned with respect to the slot in the socket, the screw-bolt may be advanced until its point I! projects into the socket, thereby preventing the insertion of a bulb or a plug for an electrical appliance. The spring-pressedplungers lock the screw-bolt in this position so that it cannot be withdrawn without the proper 2,185,103 key. When it is desired to insert a bulb or plug.

the key is inserted and the screw-bolt withdrawn sufllciently to permit the insertion of the bulb or plug. The screw-bolt is then again advanced to its forward position, thereby causing its point to grip or penetrate the threaded brass shell on the bulb or plug and thus prevent the removal thereof. At the same time the brass ring I! on.

the screw-bolt makes contact with the brass ring 46, thereby establishing an electrical circuit from conductor I I through brass rings l6 and I8 and point I! of the screw-bolt to the brass shell of the bulb or plug. Thus the simple operation of advancing the screw-bolt by means of the key both locks the lamp or plug in position and establishes the electric circuit thereto. Furthermore, when the screw-bolt is retracted to permit the removal of the bulb or plug the electric contact between the screw-bolt and conductor I1 is broken, so that the removal of the bulb or plug does not leave live contacts exposed. 1

It will now be apparent that the present invention provides a simple and effective means for preventing the unauthorized insertion or removal of electric lamp bulbs or plugs, with a very simple locking mechanism. Furthermore, it provides a simple means for making and breaking the circuit from connecter to lamp at the same time the lamp is locked or unlocked. It will also be apparent that many of the details of the specific embodiment shown in the drawing may be changed without departing from the spirit and scope of the invention.

,Conventional means for turning the lamp on and oif may be provided if desired.

We claim:

1. An electric connecter which comprises a casing, a socket in the casing adapted to receive and hold the base of. an electric lamp or plug, a threaded screwbolt sharpened at one end and so mounted in the casing as to permit the sharpened end to be aivanced into the socket and penetrate the base 0 a lamp or plug therein, said screwbolt having a slot in its shank adapted to receive a key, a pair of plungers mounted in said casing spring-pressed to enter the slot on opposite sides of the screw-bolt and thereby lock the screw-bolt, said plungers being adapted to be forced out of the slot and release the screw-bolt by the inserplug therein by the advancement of the screwbolt and for breaking the circuit by the retraction of the screw-bolt. l

2. An electric connecter which comprises a casmg, a threaded socket in the casing adaptedto receive the threaded base of an electric lamp or plug, a threaded metal screw-bolt having a relatively hard point at one end thereof so mounted in the casing as to permit the point to be advanced into the socket at the side thereof, said screw-bolt having a locking slot in its shank adapted to receive a key, a pair of plungers mounted in said casing spring-pressed to enter the slot on opposite sides of the screw-bolt and thereby lock the screw -bolt, and an electric con-' ductor mounted in the casing so as to makecontact with the screw-bolt when it is in its advanced position and thereby complete an electric circuit to the pointed end of the screw-bolt and to break contact when the screw-bolt is retracted.

3. An electric'connecter which comprises a casing, a threaded socket in the casing adapted to receive the threaded base of an electric lamp or plug, a threaded metal screw-bolt having a relatively hard point at one end thereof so mounted in the casing as to permit the point to be advanced into the socket at the side thereof, said screw-bolt having an electrically conductive beveled surface at the front thereof and a locking slot in its shank adapted to receive a key, a pair of plungers mounted in said casing spring-pressed to enter the slot on opposite sides of the screwbolt and thereby lock the screw-bolt, an electric conductor associated with the casing, and abev-y eled electricallyconductive surface connected to the conductor and positioned in "the casing so as to cooperate with the conductive surface on the 

